Vox Valvetronix VTH120 Tube Replacement(Not For The Meek)

[STRATDELUXER97]

Mr Tweaker here... :smack:
I decided I wanted to see what 12AX7 was in my 120 watt head and actually there's 2 in the amp.Both of mine were Sovtek 12AX7WA versions,though alot of guys say their's has the EH 12AX7s...

What a royal pain in the a$$ it was to get these 2 tubes out! Holy Sh!t!
On the head there are two large holes that are cut out at the bottom of the wooden cabinet..You can actually see both tubes sitting in the chassis,but good luck getting them out! :smack: The bottom tips of the preamp tubes only stick out about an inch or less away from the bottom of the metal chassis and there's no way to pull the tubes out without having to remove a gazillion screws...Even after removing the many screws around the metal chassis where both tubes reside,I still couldn't reach in and grab the tubes because on either side of the preamp tubes are metal standoffs that are in the way...I ended up very carefully using a thin bladed screwdriver and carefully pryed the tubes out of the sockets! What a stupid idea this is! :yell:

I then put my trusty set of long plate NOS RCAs into my amp and low and behold...The same scenario I ran into on my Cyber Twin,in that the amp is stronger,tighter,and warmer(Smoother)sounding than with the Sovteks,but mainly I'm hoping for reliability with the RCAs....This is a bigtime pain in a$$ and I'm warning you before you get inside of your amp to try this....It's not for the meek or un-daring...

The combo would be even worse,much worse!
The outcome was worth my time as I just knew the RCAs would be better,alot better...

John

 

[Gearjoneser]

Re: Vox Valvetronix VTH120 Tube Replacement(Not For The Meek)

I remember on one of your older posts, I warned you about how difficult they are to remove. Jeeeezuuus! I snapped off the little nipple on the top of the tube, just trying to get it out. What a pain! I had a Sovtek WA in mine, and put a Sovtek LPS in there. It does make a difference.....slight, but I can hear that the amps fidelity improved.

 

[Jag513]

Re: Vox Valvetronix VTH120 Tube Replacement(Not For The Meek)

By the thread title, I thought you were going to put up pictures of your Vox and "open-heart surgery" on it. :laugh2:

 

[Buckeyedog]

Re: Vox Valvetronix VTH120 Tube Replacement(Not For The Meek)

Man are you guys ever right. When I had my combo, I did the same thing. I was so pissed. Broke the little nipple off, then the whole thing just broke. I got the other one out ok, but with a hell of a lot of effort. Taking those rubber rings off help, but not by much. I guess they don't want people fooling with them. I just call it a dumb design!!

 

[STRATDELUXER97]

Re: Vox Valvetronix VTH120 Tube Replacement(Not For The Meek)

Man are you guys ever right. When I had my combo, I did the same thing. I was so pissed. Broke the little nipple off, then the whole thing just broke. I got the other one out ok, but with a hell of a lot of effort. Taking those rubber rings off help, but not by much. I guess they don't want people fooling with them. I just call it a dumb design!!

I didn't break any nipples off on my tubes...I'm smarter than that...I sit there and ponder at these kinds of things as I desperately think of ways to make things easier on myself...I got this mentality from years as a "Mr Goodwrench" and then all the amp mods and everything else I get my hands on..LOL...

I found it easier to very carefully get between the tube pins and the socket with a small flat bladed screwdriver and start it.After that I used a wooden chopstick and popped the tubes out the rest of the way...Putting the new tubes in was easy..Just lined em up and carefully pushed them into place..The RCAs seemed to make a very significant difference I can hear..The amp seems stronger,warmer,and rounder,but maybe it's just a placebo effect? At least I know I'm using better tubes...I don't care for the Russian Sovtek tubes from my past experiences...

John

 

[Quencho092]

Re: Vox Valvetronix VTH120 Tube Replacement(Not For The Meek)

where do you get your NOS RCA's John? I can't seem to find anybody that sells them.

 

[STRATDELUXER97]

Re: Vox Valvetronix VTH120 Tube Replacement(Not For The Meek)

where do you get your NOS RCA's John? I can't seem to find anybody that sells them.

I've had mine for over 5 years now..Bought them on E Bay.They're getting pretty scarce and pricey these days though...

John

 

[Scott_F]

Re: Vox Valvetronix VTH120 Tube Replacement(Not For The Meek)

i was wondering about that when I had mine. looked like a pain in the a$$ and I guess you guys are confirming that. If this tube is such an integral part of the power section, then a better tube should help. If I ever get one, I'll send it to you for re-tube!

 

[STRATDELUXER97]

Re: Vox Valvetronix VTH120 Tube Replacement(Not For The Meek)

i was wondering about that when I had mine. looked like a pain in the a$$ and I guess you guys are confirming that. If this tube is such an integral part of the power section, then a better tube should help. If I ever get one, I'll send it to you for re-tube!

I'd just coach you through it Scott...It's a pain in the a$$ but not impossible..I know how to do it now. :13:

John

 

[kmcguitars]

Re: Vox Valvetronix VTH120 Tube Replacement(Not For The Meek)

I was reading up on the Valvetronix. It seems like a real cool amp. One
thing I read (and I'm not sure if I read it right?) The preamp tube is
designed to work in the power section of the amp? It's that correct?

 

[Scott_F]

Re: Vox Valvetronix VTH120 Tube Replacement(Not For The Meek)

I was reading up on the Valvetronix. It seems like a real cool amp. One
thing I read (and I'm not sure if I read it right?) The preamp tube is
designed to work in the power section of the amp? It's that correct?

It's a mini power tube that is scaled up using solid state technology.

 

[STRATDELUXER97]

Re: Vox Valvetronix VTH120 Tube Replacement(Not For The Meek)

I was reading up on the Valvetronix. It seems like a real cool amp. One
thing I read (and I'm not sure if I read it right?) The preamp tube is
designed to work in the power section of the amp? It's that correct?

Yep....That's correct.. :dance:

 

[JumpMarine]

Re: Vox Valvetronix VTH120 Tube Replacement(Not For The Meek)

It could be possible to loop and attach a piece of duct tape to the top of the tube to pull it out. It must be good sticky duct tape mind you and you may need to rock the tube side to side if possible but it just might work.

 

[STRATDELUXER97]

Re: Vox Valvetronix VTH120 Tube Replacement(Not For The Meek)

It could be possible to loop and attach a piece of duct tape to the top of the tube to pull it out. It must be good sticky duct tape mind you and you may need to rock the tube side to side if possible but it just might work.

I tryed that and it didn't work..The tubes fit very tightly(On my amp)in ceramic sockets...
I have this idea though,as I always find easier and or better ways to do things...LOL...

Here's my idea..
Remove the rubber rings that sit around the preamp tubes...Use a spark plug boot remover tool(From Sears,Snap On etc..) and carefully grip around the tube and carefully rock and wiggle and pull it out...Putting the back in is really easy once you line the pins up correctly..This would save me from having to take anything apart because the tubes are visible on the head through the bottom of the wooden cabinet...If this works,I've saved myself alot of hassles...

John